Surface treating device



Dec. 23, 1952 M. P'lsANl ETAL 2,622,563

SURFACE TREATING DEVICE f Filed oct. 22, 1949 2 SHEETS- SHEET 1 50144120 L., Han/,SEN

max/5f Dec. 23, 1952 M. PlsANl ETAI.

SURFACE TREATING DEVICE 2 SHEETS-SHEET 2 Filed Oct. 22. 1949 IN VEN TOR5 AMR/o f/w/v/ FDM/m L. HA NSE/v Patented Dec. 23, 1952 SURFACE TEEATING DEVICE Mario Pisani and Edward L. Hansen, San Francisco, Calif.

Application October 22, 1949, Serial No. 122,982

6 Claims.

Another object of this invention is to provide an automatic reversing valve and actuating mechanism operated by the stroke of a reciprocating surface treating tool, such as a le, sandpaper pad or polishing pad.

We are aware that some changes may be made in the general arrangements and combinations of the several devices and parts, as well as in the details of the construction thereof without departing from the scope of the present invention as set forth in the following specication, and as dened in the following claims, hence we do not limit our invention to the exact arrangements and combinations of the said device and parts as described in the said specication, nor do we confine ourselves to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

With the foregoing and other objects in View, which will be made manifest in the following detailed description, reference is had to the ac- 2! companying drawings for the illustrative embodiment of the invention, wherein:

Fig. 1 is a sectional view of our device, the section being taken on line I-I of Fig. 7.

Fig. 2 is a reverse sectional View of our device the section being viewed in direction of arrows 2-2 of Fig. 7.

Fig. 3 is a side elevation of our device.

Fig. 4 is a sectional View taken on lines 4-4 of Fig. 1,

Fig. 5 is a sectional View taken on lines 5 5 of Fig. 1.

Fig. 6 is a sectional view taken on line 6 6 of Fig. 1.

Fig. 7 is an end view of our device, and

Fig. 8 is a fragmental sectional view showing the tool clamping means for our device.

In carrying out our invention we make use of a frame I I with a valve handle I2 projecting upwardly at its front and a rear handle I3 extending upwardly near its rear end for facilitating the gripping and holding of the tool.

The body I4 of the frame II has a longitudinal bore I6 covered at each end by a bearing plug I'I. A double action piston I8 works in the bore I6.v A piston rod I9 extends through said piston I8 and out through both bearing plugs Il, which latter are suitably packed for slidably guid- :ing said piston rod I9. y

A@n ,each end of the piston rpdIB is fixed a carriage bracket '2| which is movable in the substantially U-shaped hollow ends 22 of the frame II. A pair of guide bars 23, connected to the opposite brackets 2I, are slidable through guide holes 24 in the frame body I4 and below said bore I6, so that the brackets ZI are held in aligned position by the piston rod I9 and the guide bar 23 throughout the reciprocation thereof.

Unto the lower ends of the brackets 2| is suitably attached a tool mounting shoe 26. The finishing tools or elements can be detachably mounted on the shoe 26. For instance, a clamping plate '21, shown in Fig. 8, is held on the shoe 26 by countersunk screws 28. The plate 2I has a retaining groove 29 formed around its ends and immediately under said shoe 26. A retainer loop 3 I, pivotally anchored on the plate 21 is normally drawn by springs 32 into each groove 29 so as to clamp the ends of a surface treating element 33 such as sandpaper or polishing sheet, in place. A suitable le may be screwed in place of the clamp plate 21.

A reversing valve mechanism is provided in the frame body for controlling the intake and eX- haust of the cylinder bore I6, Said valve mechanism is adapted to be operated or actuated by the end brackets 2| at the respective ends of the carriage stroke for reversing the piston action.

The pressure medium, such as compressed air, is supplied to the cylinder bore I6, through a passage 34 in the valve handle I'2 which leads from an outside hose, not shown, into a valve bore 36 parallel with the cylinder bore I6 and longitudinal in the body I4 between said bore I6 and the handles I2 and I3. The passage 34 is normally closed by a suitable spring pressed poppet valve 31, in the handle I2, the valve stem 3B of which valve extends to the outside of the handle I2 Vand has a suitable button 39 on it for manual pressing of the valve to open position. The passage 34 terminates in an intake port 4I at about the middle of the valve bore 36.

On the opposite sides of the intake port 4I and equally spaced therefrom are outlet ports 42 and 43, both of which connect to an exhaust passage 44 leading from said body I4 and through said valve handle I2 to an outside conduit not shown.

The cylinder bore I6 has near each end thereof a port 46, each of which alternately functions as intake port or exhaust port according to the direction of piston stroke in the cylinder bore I6. From each cylinder port 46 eXtends'a connecting passage 41, with a pair of spaced valve ports 48 and 49 near the end of the valve bore 36 farthest from the respective cylinder port 46.

A sliding valve 5I reciprocates in the valve bore 36. The sliding valve 5I has three spaced cylindrical valve heads 52, 53 and 54 connected by a valve stem 56. Guide and abutment valve stems 51 extend outwardly at each end of the valve 5| and are slidable through plug packings 58 in the ends of the valve bore 35. On the outer end of each guide stem 51 is a cushion 59 for abutment by the respective carriage bracket 2l for reversing the valve at the end of each stroke of the piston The heads 52, 53 and 55 are so spaced that at one end of the valve stroke one set of the spaced valve ports 48 and 159 are exposed on the opposite sides of the head 52 and are connected to the intake port 4| between said head 52 and the middle head 53, while the other set of ports 58 and 49 at the other end of the valve bore 35 are communicated with the adjacent outlet port 43 between the other end head 54 and the middle head 53.

This arrangement provides for the introduction of the pressure medium to one side of the piston, as well as providing an air cushion on the outside of the respective end valve head 52 or 54.

The length of each guide stem 51 is such that the stem 51 in its retracted position extends beyond the valve bore 35 to a distance equal to the spacing between the end of valve bore 36 and the adjacent carriage bracket 2| at the end of the stroke of said bracket 2| toward the end of the valve bore 36. When the valve 5| is pushed to another stroke the retracted stem 51 is pushed to a further distance equal to the slide valve stroke and thus is in the path of the carriage bracket 2| upon the return stroke of the latter.

In Fig. 2 the exhaust passages are shown in dash and dot broken lines to indicate the relative positions thereof. The horizontal portion of the connecting passage 41 would be superimposed upon the connecting passage shown in broken lines.

The double port at each end of each connecting passage 41 results in ythe introduction of the pressure medium between the respective valve heads 52 or 54 and the adjacent valve plug 58. This pressure pocket serves the purposes of moving the valve 5| to its iinal reversed position after the original tapping of the cushion 59 of the guide stem 51 by the respective carriage bracket 2| and to hold the valve 5| in its extreme position firmly without vibration until the valve 5| is reversed by being struck by the other carriage bracket 2| This pocket also cushions the stroke of the valve 5| as it exhausts gradually through the adjacent port. This results in smooth, positive operation, which reciprocates the tool repeatedly without undue vibration of the hand of the operator and without undue wear on the moving parts. There is no so called neutral or dead position in this device because the valve is always pushed to one of its extreme positions at each stroke, ready for the next operation, as long as pressure medium is fed to the valve 5| and to the piston.

The nishing or treating tool can be quickly interchanged on the reciprocating shoe of this device. Thereafter the device is easily and positively operated by holding the handles and pushing the valve button.

We claim:

1. A reciprocating tool holder comprising a body having a cylinder bore and valve bore parallel with and alongside the cylinder bore, a port adjacent each end of the cylinder bore, a passage connecting each port to the end portion of the valve bore farthest from the respective port, a valve port extended from each passage to the valve bore, said valve ports. being spaced `from one another longitudinally along said valve bore but being generally intermediate between the ends of the valve bore, an intake valve port in said valve bore intermediate between said valve ports, controlled means to connect said intake valve port to a pressure medium, a pair of spaced exhaust valve ports each being located generally between a valve port and the adjacent end of said passage, said exhaust valve ports being connected to an exhaust system, a piston working in said cylinder bore, the ends of said bores being closed, piston rods extending in opposite directions from said piston and to the outside of said cylinder bore ends, a frame on said piston rods reciprocable with said piston relatively to said body, means to mount a tool on said frame and under said body for reciprocation with respect to said body, a slide valve working in said valve bore, said slide valve having a pair of spaced intermediate transfer chambers, one of said chambers aligning with one of said exhaust valve ports as the other is aligned with said intake valve port and said chambers being aligned with the respective valve ports of said passages, and a cushion chamber in each of said end portions of the valve bore, said passage communicating with said adjacent cushion chamber; valve rods extended from the opposite ends of said sliding valve and through the closed ends of said valve bore and in the path of said reciprocating frame to be abutted and pushed by said frame at the ends of the respective frame strokes for reversing said sliding valve position with respect to said intake and exhaust ports for reciprocating said piston.

2. A reciprocating tool holder comprising a body having a cylinder bore and valve bore parallel with and alongside the cylinder bore, a port adjacent each end of the cylinder bore, a passage connecting each port to the end portion of the valve bore farthest from the respective port, a valve port extended from each passage to the valve bore, said valve ports being spaced from one another longitudinally along said valve bore but being generally intermediate between the ends of the valve bore, an intake valve port in said valve bore intermediate between said valve ports, controlled means to connect said intake valve port to a pressure medium, a pair of spaced exhaust valve ports each being located generally between a valve port and the adjacent end of said passage, said exhaust valve ports being connected to an exhaust system, a piston working in said cylinder bore, the ends of said bores being closed, piston rods extending in opposite directions from said piston and to the outside of said cylinder bore ends, a frame on said piston rods reciprocable with said piston relatively to said body, means to mount a tool on said frame and under said body for reciprocation with respect to said body, a slide valve working in said valve bore, said slide valve having a pair of spaced intermediate transfer chambers, one of said chambers aligning with one of said exhaust valve ports as the other is aligned with said intake valve port and said chambers being aligned with the respective valve ports of said passages, and a cushion chamber in each of said end portions of the valve bore, said passage communicating with said adjacent cushion chamber; valve rods extended from the opposite ends of said sliding valve and through the closed ends of said valve bore and in the path of said reciproeating frame to be abutted and pushed by said frame at the ends of the respective frame strokes for reversing said sliding valve position with respect to said intake and exhaust ports for reciprocating said piston, a handle on said body, said controlled connecting means including an intake conduit in said handle leading to said intake port.

3. In a reciprocating tool holder of the characacter described, a body, a handle on the body, a reciprocable frame on the body, means to mount a tool on said frame for reciprocation; a pressure medium operated device in the body for imparting reciprocating movement to said frame, a system of passages and ports in said body for controlling said pressure medium for the opposite strokes of reciprocation, a slide valve in the body interconnected into said system for reversing the action of said pressure medium after each stroke of said frame, abutment members extended from said slide valve into the path of the frame each to be abutted by the frame at the end of a stroke to shift the valve into reversing position, a piston member at each end of said valve, a chamber in said body outside of each piston member, said system of passages including a conduit leading from each end of said body at said device into the chamber beyond said piston member at the respective opposite end of said body, and valve passages through said slide valve connecting the respective conduits alternately to the intake and exhaust of said pressure medium, the conduit connected to said intake supplying said pressure medium to one end of said body for operating said device and into the chamber at the opposite end of said body for holding said piston member in position until the shifting of said valve for alternate operation.

4. In a reciprocating tool holder of the character described, a body, a handle on the body, a reciprocable frame on the body, means to mount a tool on said frame for reciprocation; pressure medium operated device in the body for imparting reciprocating movement to said frame, a system of passages and ports in said body for controlling said pressure medium for the opposite strokes of reciprocation, a slide valve in the body interconnected into said system for reversing the action of said pressure medium after each stroke of said frame, abutment members extended from said slide valve into the path of the frame each to be abutted by the frame at the end of a stroke Yto shift the valve into reversing position, a piston member at each end of said valve, a chamber in said body outside of each piston member, said system of passages including a conduit leading from each end of said body at said device into the chamber beyond said piston member at the respective opposite end of said body, and valve passages through said slide valve connecting the respective conduits alternately to the intake and exhaust of said pressure medium, the conduit connected to said intake supplying said pressure medium to one end of said body for operating said device and into the chamber at the opposite end of said body for holding said piston membei` in position until the shifting oi said valve for alternate operation, said slide valve being slidable parallel with the reciprocation of said frame.

5. In a reciprocating tool of the character described, a body adapted to be held in the hand of the operator, a cylinder in said body, a valve cylinder in said body parallel with and alongside said rst cylinder, a piston working in said first cylinder, a tool carriage connected to said piston for reciprocation with said piston with respect to said body, a piston valve in said valve cylinder having spaced chambers, abutment elements extended oppositely from said piston valve in the path of said carriage for abutment by said carriage for shifting said piston valve in opposite positions for the respective strokes of the piston in said cylinder, a pair of conduits each leading from an end portion of the rst cylinder into the end portion of the valve cylinder opposite the other end of said i'lrst cylinder and also into the chamber nearest to said other end for simultaneously conducting pressure medium to said end portion of the valve cylinder and through said nearest valve chamber for moving and holding said valve in the respective shifted position during the corresponding stroke of said piston, an intake port in said valve cylinder aligned with one of said chambers in each extreme position of said valve to introduce pressure medium alternately to opposite sides of said piston in said rst cylinder as the valve is shifted by said carriage, and exhaust ports on the valve cylinder substantially equally spaced on opposite sides of said intake port to alternately connect to the chamber remote from the intake port.

6. In a reciprocating tool of the character described, a body adapted to be held in the hand of the operator, a cylinder in said body, a valve cylinder in said body parallel with and alongside said first cylinder, a piston Working in said rst cylinder, a tool carriage connected to said piston for reciprocation with said piston with respect to said body, a piston valve in said valve cylinder having spaced chambers, abutment elements extended oppositely from said piston valve in the path of said carriage for abutment by said carriage for shifting said piston valve in opposite positions for the respective strokes of the piston in said cylinder, an intake port in said valve cylinder aligned with one of said chambers in each extreme position of said valve to introduce pressure medium alternately to opposite sides of said piston in said rst cylinder as the valve is shifted by said carriage, exhaust ports on the valve cylinder substantially equally spaced on opposite sides of said intake port to alternately connect to the chamber remote from the intake port, a pair of conduits each communicating an end portion of the rst cylinder with the end portion of the valve cylinder opposite the other end of said iirst cylinder, and also with the valve cylinder at the chamber nearest to said other end to conduct part of said pressure medium passing through said chamber to said end portion of said valve cylinder for simultaneous acting on the piston and upon the valve for holding said valve in shifted position corresponding to the respective stroke of the piston.

MARIO PISANI. EDWARD L. HANSEN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 168,439 Wilson Oct. 5, 1875 479,356 Farrell July 19,1892 734,276 Metcale et al July 21, 1903 997,627 Lindholm July 11, 1911 1,136,796 Hammar Apr. 20, 1915 1,766,010 Binderup June 24, 1930 1,818,361 Schwabe Aug. 11, 1931 1,956,988 Lapointe May 1, 1934 2,103,444 Bauch Dec. 28, 1937 

